A navigation apparatus simplifies the travel of a vehicle by displaying the route to a destination and by periodically displaying specific guidance. For this reason, the use of navigation apparatuses has been steadily increasing. In addition, a navigation system has been proposed in which the navigation apparatus is activated from an external terminal such as a personal computer or a telephone, and the destination is thereby set in the navigation apparatus (refer, for example, to Patent Document 1).
This navigation system can set the destination in a navigation apparatus that is mounted in a vehicle by using an external terminal before the driver enters the vehicle, and can quickly begin the route guidance after the driver enters the vehicle.
In the navigation system described above, however, in the case in which an external terminal remotely controls the navigation apparatus by activating the navigation apparatus mounted in the vehicle using Internet communication, it is necessary for the external terminal to acquire the IP address of the navigation apparatus. However, a control server newly assigns a different IP address each time the navigation apparatus is activated. Thus, it has not been possible for the external terminal to acquire the new IP address. As a result, remotely control of the destination setting and the like from an external terminal has been difficult.    [Patent Document 1] Japanese Patent Application No. JP-A-H6-243395